PostProcess Technologies Uses Hybrid DECI Duo Solution to Achieve Excellent Surface Finish for 3D Printed Shrouded Impellers

Exacting Surface Finishing of Complex 3D Printed Metal Geometries.

PostProcess Technologies, which expanded its channel partner coverage in North America this spring, is well known for its software and post-printing solutions. With its automated Hybrid DECI Duo solution, PostProcess helps its customers achieve excellent surface finish standards and replicable results for complex metal parts.

Recently, PostProcess demonstrated in a new case study how well its technology can help other companies. The subject was Ingersoll Rand, a $14 billion global industrial manufacturing company that specializes in compressed air technologies. The company uses 3D printing for its shrouded impellers, which improve the performance of a compressor package more than open impellers because there is no clearance between the stationary inlet and the impeller, so no slip losses occur as a result of compression gas recirculating in the space.

The design for shrouded impellers, which rotate 60,000 RPM, has very tight tolerances in order to meet aerodynamic testing. In addition, the blades need excellent surface finishing, and it takes months to build using conventional forms of manufacturing. So Ingersoll’s engineering team, needing to commercialize its shrouded impeller design, turned to 3D printing because of its complete design freedom; the technology also makes it possible to build the part as monolithic, so no welding is required. But, in order for 3D printed parts to meet performance thresholds, they do require outstanding surface finishes.

Ingersoll 3D prints its shrouded impellers out of titanium and nickel alloy, but they unfortunately come off the print bed at an Ra (roughness average) value that doesn’t meet the engineering team’s specifications. The team has tried everything from manual sanding and grinding tools to chemical etching, but the results were inconsistent and did not have the necessary, repeatable quality needed to produce end parts within the required specifications.

The company needed to find a replicable process that would provide them with the necessary surface finish for its shrouded impeller’s complex geometry, in order to, as PostProcess wrote in its case study, “drive a measurable increase in efficiency for its advanced air compressors.”

So, Ingersoll turned to PostProcess in hopes that the company could work with complex metal part geometries, like organic shapes and internal channels, and help achieve repeatable results and excellent surface finish standards for its shrouded impellers.

Automated DECI Duo for Post-Print Support Removal & Surface Finishing.

PostProcess delivered a “transformative outcome” for Ingersoll’s 3D printed titanium and nickel alloy parts, thanks to its patent-pending, automated Hybrid DECI Duo solution. The Hybrid DECI Duo – a single, multi-functioning, data-driven system – promises fast cycle times for even the most complex of parts Designed to optimize production floor space, the system also includes noise reducing features for a low dBa, an LED lighted chamber, and a manual mode for hands-on part finishing when needed.

The system also uses PostProcess’ proprietary AUTOMAT3D software, in order to optimize energy and exclusive chemistry, which includes detergents and suspended solids so the geometries maintain their fine-feature details while still receiving the desired surface finish.

“We have chosen the DECI Duo because of its repeatability, minimal setup, processing times, and cost of ownership. Photochemical machining, extrude honing, and micro polishing or micro machining all yield very good results when applied correctly, however extensive tooling and equipment costs, setup times, and required DOE’s prior to applying the surface finishing method to obtain a repeatable process have made the DECI Duo a better option,” said Ioannis Hatziprokopiou, Mechanical Engineer, New Product Development, Ingersoll Rand Compression Technologies and Services.

“In addition, some of aforementioned finishing techniques unevenly remove material inside the flow path of the impeller, whereas the DECI Duo uniformly treats the entire surface of the flow path. The final geometry of the flow path must remain as unaltered as possible after post-processing of any kind.”

3D printed shrouded impellers were
implemented on the last 3 stages of this 6 stage 6R3MSGEP+4/30 engineered air booster machine.

The PostProcess solution established operating settings that were in line with Ingersoll’s standards using benchmark parts. Then, the DECI Duo was able to consistently finish metal parts that were able to successfully pass exacting aerodynamic tests.

Ingersoll came to PostProcess with a need for high quality and requirements in consistency and repeatability. But, it’s also achieved additional advantages from working with the company, such as cost savings and ease of operation.

In addition, the DECI Duo also produced an average of 70-80% reduction in Ra for parts run for 20 minutes or less.

Discuss this story and other 3D printing topics at 3DPrintBoard.com or share your thoughts below.